QUESTION $13$

$3\mathrm{.}5-2$c$.$ TCP sequence and ACK numbers $($c$).$ ;Consider again the figure above $($in question $3\mathrm{.}5-2$a$)$ where a TCP sender sends $8$ TCP segments at t $=1,2,3,4,5,6,7,8$ and the segment sent at t$=4$ is lost, as is the ACK segment sent at t$=7.$

What is the ACK value carried in the receiver$-$to$-$sender ACK sent at t $=8?$

$100$

$400$

None of these other answers.

$200$

$3$

$300$